Improving GPT-5.6 Sol in ChatGPT-and expanding access to GPT-5.6 Luna for free users

OpenAI announced updates to ChatGPT on August 6, 2026, improving GPT-5.6 Sol for Plus and Pro users and expanding access to GPT-5.6 Luna for free users. The company said the updates improve everyday conversations while expanding access for free users. For Plus and Pro users, GPT-5.6 Sol is updated to be more reliable with facts and provide more focused answers. A new slider lets users choose how much thought ChatGPT puts into each response. The same model now powers both Instant responses and deeper reasoning, creating one consistent experience. In internal evaluations of financial, medical, and legal prompts, responses containing at least one factual error were about 68% less common with GPT-5.6 Sol than with GPT-5.5 Instant. For free users, the default model is updated to GPT-5.6 Luna with unlimited text chats. A new Think button lets free users access higher reasoning for harder questions. In internal evaluations, responses containing at least one factual error were about 62% less common with GPT-5.6 Luna than with GPT-5.5 Instant. Plus and Pro users can access the updated GPT-5.6 Sol and the new slider starting today. GPT-5.6 Luna will become the default model for free users.